Drilling systems which use a pressurized stream of air or liquid are well known in the art. Typically, these systems employ a stream of air or water that is discharged from a high pressure lance. These systems operate in the low pressure ranges, i.e. 100-200 psi., to cut through earthen soil or soft materials. Often, these systems are used to excavate holes and are simple in operation. The operator merely aims the lance and activates the pressure supply to discharge the air or water. The hole is created as the air or water pushes away the soil. There are other systems that also provide a method and apparatus to recover the loosened soil. Two similar methods and devices which recover the loosened soil are described in literature published by the Miller Pipeline Corporation of Long Beach, Calif. and SoftDig Corporation of West Chester, Pa.
Both the Miller and the SoftDig techniques require a two person crew to operate their respective high pressure drilling devices. In this two person crew arrangement, the first crew member aims the high pressure air lance towards the soil which is to be loosened. The second crew member operates a separate vacuum line near the position where the high pressure air lance is performing the cutting. When activated, the vacuum line recovers the loosened soil.
These systems have the initial drawback that they require two crew members to operate. Additionally, these devices are directed at excavating soil for the purpose of exposing utility lines. The device and method disclosed by Miller and SoftDig are intended to effectuate the drilling process without damaging the utility lines. In operation, because the air lance and vacuum lines are not integrated, the drilled soil is not entirely contained by the vacuum line, resulting in a dust discharge from the excavated hole. Thus, Miller and SoftDig are not directed towards a drilling apparatus and a drilling method that recovers all of the loosened soil which was drilled.
Additionally, there are also drilling systems which use a flowable particulate solid, like sand. Sand blasting is one technique that uses sand to strip away a surface layer of an object. However, sand blasting, generally, is intended to reveal the inner portion of the object and is not directed at recovering the material that was stripped away.
It is accordingly, an object of the present invention to provide a drill which is capable of employing a pressurized gas, liquid, or particulate solid to achieve the drilling.
It is another object of the present invention is to provide a drill which recovers all of the material that was drilled.
Yet another object of the present invention is to provide a drill which can be used by a single operator.
Still another object of the present invention is to provide an improved drill which is simple in construction, economical to manufacture, and simple, efficient, and safe to use.